Modified solvent accessibility free energy prediction analysis of cyclic urea inhibitors binding to the HIV-1 protease

One of the most successful drug targets against AIDS in thelast decade has been the HIV-1 protease (HIV-1 PR), an enzymethat processes the polyprotein gene products into active replicativeviral proteins. In our quest for a wide-ranging, binding freeenergy function we have extended the solvent accessibility freeenergy predictor (SAFE_p) method, recently developed for peptidicHIV-1 PR inhibitors, to the study of the binding of cyclic urea(CU) HIV-1 PR inhibitors. Our results show that there is a needfor a specific term depicting polar contacts to be added tothe original SAFE_p analytical expression, an outcome not seenin our studies of HIV-1 PR peptidic inhibitors. Nevertheless,despite the higher profile of the electrostatic interactionsin the binding of the CU inhibitors, our analysis indicatesthat CU inhibitor binding is still driven by the hydrophobicentropic contribution, as much as for the peptidic inhibitors.     

Simple and efficient inductive telemetry system with data and power transmission

This paper presents an inductive telemetry system useful for isolated applications that have to be powered and/or controlled from outside. The transmitter is based on a Class-E amplifier with ASK modulation generated with a resonant modulation to obtain the different levels to transmit. In the receiver two possible configurations, parallel and serial, are studied and the serial configuration is proposed to reduce the effect of the rectifier and the filter over the received signal. Also an ASK demodulator is fabricated in an ASIC. All the system (transmitter-receiver) has been tested and a 60% of efficiency in power transmission is obtained at a distance of 10 mm. For the data link a bit rate 1 Mbps with a carrier of 8 MHz at a distance of 20 mm has been obtained.     

Using the node's experience from previous transmissions to improve the communication in an indoor localization system

Although originally the wireless sensor networks (WSN) were designed for transmitting environmental parameters with a low data rate, there is a growing need to use these networks for applications that require high throughput, such as real time localization systems (RTLS).     

Spectroscopy of atomic chains with tunneling microscopy

Recently, it has been possible to create metallic chains down to seven-atom long. This has two implications. Experimentally it is necessary to have algorithms that allow converting measured data into microscopic information as, for example, processing a current-voltage curve to obtain electronic density of states (DOS). From a theoretical standpoint, we have a new framework to test extant theories and to further develop them. With this in mind, we present a new theoretical solution to the problem of mapping scanning tunneling microscopy current-voltage curves into DOS-energy curves. Our model is based on a self-consistent solution to the quantum problem of electrons in the presence of an array of attractive centers. The problem, being simpler than its three-dimensional counterparts is solved exactly for DOS and for the current-voltage curves. The main results are that the current-voltage peaks at the position of the energies of the electron in the chain and, when an impurity is present in the chain, its chemical information can be extracted from the value of analytical curves.